Optimum design of a planing boat's hull form

This paper is concerned with an approach to obtain the minimum resistance hull form parameter set x (X-1, X-2 ........., X-11) to a planing boat model from many towing test data. About ten X-i s, which are necessary to form a hull, have been transformed into the dimensionless numbers for the law of similarity. Total resistance coefficient at a planing condition is selected as objective function and its minimum is searched under restrictive conditions. X-i 's correlations in a hull form, X-i being within experimental data and near their mean values, and other requirements are taken into the conditions. Penalty terms are added to make modified objective function. The terms which are made from the above conditions and work to gain a larger number when the search is done far from the optimum. Against an initial x in the above feasible region, the modified objective function is successively minimized to get the optimum x, which means successive reformation of hull. A changed principal dimension affects the other ones because of their requiring correlations in a hull form, which will perplex designers. How to keep the correlation conditions in satisfaction will be proposed as a successful example.